fix: lazy Stripe init (unblocks test suite) + add auth/keys unit tests

- billing.ts: Stripe now initialized lazily via getStripe() instead of at module load
  This prevents test suite crash when STRIPE_SECRET_KEY env var is not set
- Add src/middleware/__tests__/auth.test.ts (6 tests): key extraction from
  Bearer header, X-API-Key header, query param; 401/403 responses; priority order
- Add src/services/__tests__/keys.test.ts (6 tests): getTierLimit for all tiers
- Total: 61 tests passing, 0 failures

src/middleware/__tests__/auth.test.ts

@@ -0,0 +1,118 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { authMiddleware } from '../auth.js'
+
+// Mock the keys service
+vi.mock('../../services/keys.js', () => ({
+  isValidKey: vi.fn(),
+  getKeyInfo: vi.fn(),
+}))
+
+const { isValidKey, getKeyInfo } = await import('../../services/keys.js')
+const mockIsValidKey = vi.mocked(isValidKey)
+const mockGetKeyInfo = vi.mocked(getKeyInfo)
+
+function mockReq(overrides: any = {}): any {
+  return {
+    headers: {},
+    query: {},
+    ...overrides,
+  }
+}
+
+function mockRes(): any {
+  const res: any = {}
+  res.status = vi.fn().mockReturnValue(res)
+  res.json = vi.fn().mockReturnValue(res)
+  return res
+}
+
+describe('authMiddleware', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('should return 401 when no API key is provided', async () => {
+    const req = mockReq()
+    const res = mockRes()
+    const next = vi.fn()
+
+    await authMiddleware(req, res, next)
+
+    expect(res.status).toHaveBeenCalledWith(401)
+    expect(res.json).toHaveBeenCalledWith(expect.objectContaining({ error: expect.stringContaining('Missing API key') }))
+    expect(next).not.toHaveBeenCalled()
+  })
+
+  it('should extract key from Bearer authorization header', async () => {
+    mockIsValidKey.mockResolvedValueOnce(true)
+    mockGetKeyInfo.mockResolvedValueOnce({ key: 'snap_abc123', tier: 'pro', email: 'test@test.com', createdAt: '2024-01-01' })
+    
+    const req = mockReq({ headers: { authorization: 'Bearer snap_abc123' } })
+    const res = mockRes()
+    const next = vi.fn()
+
+    await authMiddleware(req, res, next)
+
+    expect(mockIsValidKey).toHaveBeenCalledWith('snap_abc123')
+    expect(next).toHaveBeenCalled()
+    expect(req.apiKeyInfo).toBeDefined()
+  })
+
+  it('should extract key from X-API-Key header', async () => {
+    mockIsValidKey.mockResolvedValueOnce(true)
+    mockGetKeyInfo.mockResolvedValueOnce({ key: 'snap_xyz789', tier: 'starter', email: 'a@b.com', createdAt: '2024-01-01' })
+    
+    const req = mockReq({ headers: { 'x-api-key': 'snap_xyz789' } })
+    const res = mockRes()
+    const next = vi.fn()
+
+    await authMiddleware(req, res, next)
+
+    expect(mockIsValidKey).toHaveBeenCalledWith('snap_xyz789')
+    expect(next).toHaveBeenCalled()
+  })
+
+  it('should extract key from query parameter', async () => {
+    mockIsValidKey.mockResolvedValueOnce(true)
+    mockGetKeyInfo.mockResolvedValueOnce({ key: 'snap_qp1', tier: 'business', email: 'c@d.com', createdAt: '2024-01-01' })
+    
+    const req = mockReq({ query: { key: 'snap_qp1' } })
+    const res = mockRes()
+    const next = vi.fn()
+
+    await authMiddleware(req, res, next)
+
+    expect(mockIsValidKey).toHaveBeenCalledWith('snap_qp1')
+    expect(next).toHaveBeenCalled()
+  })
+
+  it('should return 403 for invalid API key', async () => {
+    mockIsValidKey.mockResolvedValueOnce(false)
+    
+    const req = mockReq({ headers: { 'x-api-key': 'invalid_key' } })
+    const res = mockRes()
+    const next = vi.fn()
+
+    await authMiddleware(req, res, next)
+
+    expect(res.status).toHaveBeenCalledWith(403)
+    expect(res.json).toHaveBeenCalledWith(expect.objectContaining({ error: expect.stringContaining('Invalid API key') }))
+    expect(next).not.toHaveBeenCalled()
+  })
+
+  it('should prefer Bearer header over X-API-Key and query', async () => {
+    mockIsValidKey.mockResolvedValueOnce(true)
+    mockGetKeyInfo.mockResolvedValueOnce({ key: 'snap_bearer', tier: 'pro', email: 'e@f.com', createdAt: '2024-01-01' })
+    
+    const req = mockReq({
+      headers: { authorization: 'Bearer snap_bearer', 'x-api-key': 'snap_xapi' },
+      query: { key: 'snap_query' }
+    })
+    const res = mockRes()
+    const next = vi.fn()
+
+    await authMiddleware(req, res, next)
+
+    expect(mockIsValidKey).toHaveBeenCalledWith('snap_bearer')
+  })
+})

src/routes/billing.ts

@@ -5,12 +5,21 @@ import { createPaidKey, downgradeByCustomer, updateEmailByCustomer } from "../se
 
 const router = Router();
 
-const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!, {
-  apiVersion: "2025-01-27.acacia" as any,
-});
+let _stripe: Stripe | null = null;
+function getStripe(): Stripe {
+  if (!_stripe) {
+    if (!process.env.STRIPE_SECRET_KEY) {
+      throw new Error("STRIPE_SECRET_KEY environment variable is not set");
+    }
+    _stripe = new Stripe(process.env.STRIPE_SECRET_KEY, {
+      apiVersion: "2025-01-27.acacia" as any,
+    });
+  }
+  return _stripe;
+}
 
 const BASE_URL = process.env.BASE_URL || "https://snapapi.eu";
-const WEBHOOK_SECRET = process.env.STRIPE_WEBHOOK_SECRET!;
+const WEBHOOK_SECRET = process.env.STRIPE_WEBHOOK_SECRET || "";
 
 // DocFast product ID — NEVER process events for this
 const DOCFAST_PRODUCT_ID = "prod_TygeG8tQPtEAdE";
@@ -33,27 +42,27 @@ async function getOrCreatePrice(name: string, amount: number, description: strin
   if (priceCache[name]) return priceCache[name];
 
   // Search for existing product by name
-  const products = await stripe.products.search({ query: `name:"${name}"` });
+  const products = await getStripe().products.search({ query: `name:"${name}"` });
   let product: Stripe.Product;
 
   if (products.data.length > 0) {
     product = products.data[0];
     logger.info({ productId: product.id, name }, "Found existing Stripe product");
   } else {
-    product = await stripe.products.create({ name, description });
+    product = await getStripe().products.create({ name, description });
     logger.info({ productId: product.id, name }, "Created Stripe product");
   }
 
   snapapiProductIds.add(product.id);
 
   // Check for existing price
-  const prices = await stripe.prices.list({ product: product.id, active: true, limit: 1 });
+  const prices = await getStripe().prices.list({ product: product.id, active: true, limit: 1 });
   if (prices.data.length > 0 && prices.data[0].unit_amount === amount) {
     priceCache[name] = prices.data[0].id;
     return prices.data[0].id;
   }
 
-  const price = await stripe.prices.create({
+  const price = await getStripe().prices.create({
     product: product.id,
     unit_amount: amount,
     currency: "eur",
@@ -77,7 +86,9 @@ async function initPrices() {
   logger.info({ productIds: [...snapapiProductIds], prices: { ...priceCache } }, "SnapAPI Stripe products initialized");
 }
 
-initPrices().catch(err => logger.error({ err }, "Failed to initialize Stripe prices"));
+if (process.env.STRIPE_SECRET_KEY) {
+  initPrices().catch(err => logger.error({ err }, "Failed to initialize Stripe prices"));
+}
 
 // Helper: check if event belongs to SnapAPI
 async function isSnapAPIEvent(event: Stripe.Event): Promise<boolean> {
@@ -91,7 +102,7 @@ async function isSnapAPIEvent(event: Stripe.Event): Promise<boolean> {
     if (event.type === "checkout.session.completed") {
       const session = obj as Stripe.Checkout.Session;
       if (session.subscription) {
-        const sub = await stripe.subscriptions.retrieve(session.subscription as string, { expand: ["items.data.price.product"] });
+        const sub = await getStripe().subscriptions.retrieve(session.subscription as string, { expand: ["items.data.price.product"] });
         const item = sub.items.data[0];
         const prod = item?.price?.product;
         productId = typeof prod === "string" ? prod : prod?.id;
@@ -107,7 +118,7 @@ async function isSnapAPIEvent(event: Stripe.Event): Promise<boolean> {
         productId = typeof prod === "string" ? prod : (prod as any)?.id;
         // If product not expanded, fetch it
         if (!productId && item.price?.id) {
-          const price = await stripe.prices.retrieve(item.price.id);
+          const price = await getStripe().prices.retrieve(item.price.id);
           productId = typeof price.product === "string" ? price.product : (price.product as any)?.id;
         }
       }
@@ -175,7 +186,7 @@ router.post("/checkout", async (req: Request, res: Response) => {
     const planDef = PLANS[plan];
     const priceId = await getOrCreatePrice(planDef.name, planDef.amount, planDef.description);
 
-    const session = await stripe.checkout.sessions.create({
+    const session = await getStripe().checkout.sessions.create({
       mode: "subscription",
       payment_method_types: ["card"],
       line_items: [{ price: priceId, quantity: 1 }],
@@ -222,7 +233,7 @@ router.get("/success", async (req: Request, res: Response) => {
     const sessionId = req.query.session_id as string;
     if (!sessionId) return res.status(400).send("Missing session_id");
 
-    const session = await stripe.checkout.sessions.retrieve(sessionId, { expand: ["subscription"] });
+    const session = await getStripe().checkout.sessions.retrieve(sessionId, { expand: ["subscription"] });
     const email = session.customer_details?.email || session.customer_email || "unknown@snapapi.eu";
     const plan = session.metadata?.plan || "starter";
     const tier = PLANS[plan]?.tier || "starter";
@@ -306,7 +317,7 @@ router.post("/webhook", async (req: Request, res: Response) => {
     const sig = req.headers["stripe-signature"] as string;
     if (!sig) return res.status(400).send("Missing signature");
 
-    const event = stripe.webhooks.constructEvent(req.body, sig, WEBHOOK_SECRET);
+    const event = getStripe().webhooks.constructEvent(req.body, sig, WEBHOOK_SECRET);
 
     // Filter: only process SnapAPI events
     if (event.type !== "customer.updated") {

src/services/__tests__/keys.test.ts

@@ -0,0 +1,28 @@
+import { describe, it, expect } from 'vitest'
+import { getTierLimit } from '../keys.js'
+
+describe('getTierLimit', () => {
+  it('should return 100 for free tier', () => {
+    expect(getTierLimit('free')).toBe(100)
+  })
+
+  it('should return 1000 for starter tier', () => {
+    expect(getTierLimit('starter')).toBe(1000)
+  })
+
+  it('should return 5000 for pro tier', () => {
+    expect(getTierLimit('pro')).toBe(5000)
+  })
+
+  it('should return 25000 for business tier', () => {
+    expect(getTierLimit('business')).toBe(25000)
+  })
+
+  it('should return 100 for unknown tier', () => {
+    expect(getTierLimit('enterprise')).toBe(100)
+  })
+
+  it('should return 100 for empty string', () => {
+    expect(getTierLimit('')).toBe(100)
+  })
+})